/* 全局样式 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-color: #1a1a1a;
    --secondary-color: #333;
    --accent-color: #e63946;
    --text-color: #333;
    --text-light: #666;
    --bg-color: #fff;
    --bg-light: #f8f9fa;
    --bg-dark: #1a1a1a;
    --border-color: #e0e0e0;
    --shadow: 0 2px 20px rgba(0, 0, 0, 0.1);
    --shadow-hover: 0 4px 30px rgba(0, 0, 0, 0.15);
    --transition: all 0.3s ease;
}

body {
    font-family: 'PingFang SC', 'Microsoft YaHei', -apple-system, BlinkMacSystemFont, sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background: var(--bg-color);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* 导航栏 */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    box-shadow: var(--shadow);
}

.header .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 70px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 12px;
}

.logo-icon {
    width: 45px;
    height: 45px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: #fff;
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: bold;
    font-size: 18px;
}

.logo-text {
    font-size: 22px;
    font-weight: 600;
    color: var(--primary-color);
}

.nav {
    display: flex;
    gap: 40px;
}

.nav-link {
    text-decoration: none;
    color: var(--text-color);
    font-weight: 500;
    position: relative;
    padding: 10px 0;
    transition: var(--transition);
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--accent-color);
    transition: var(--transition);
}

.nav-link:hover::after,
.nav-link.active::after {
    width: 100%;
}

.header-actions {
    display: flex;
    gap: 15px;
}

/* 按钮样式 */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 12px 24px;
    border-radius: 8px;
    font-size: 14px;
    font-weight: 500;
    text-decoration: none;
    cursor: pointer;
    transition: var(--transition);
    border: none;
}

.btn-primary {
    background: var(--primary-color);
    color: #fff;
}

.btn-primary:hover {
    background: var(--secondary-color);
    transform: translateY(-2px);
    box-shadow: var(--shadow);
}

.btn-outline {
    background: transparent;
    color: var(--primary-color);
    border: 2px solid var(--primary-color);
}

.btn-outline:hover {
    background: var(--primary-color);
    color: #fff;
    transform: translateY(-2px);
}

.btn-lg {
    padding: 16px 32px;
    font-size: 16px;
}

/* 首页横幅 */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    padding-top: 70px;
    overflow: hidden;
}

.hero-bg {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(135deg, #f5f5f5 0%, #e8e8e8 100%);
    z-index: -2;
}

.hero-bg::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background:
        radial-gradient(circle at 20% 50%, rgba(230, 57, 70, 0.05) 0%, transparent 50%),
        radial-gradient(circle at 80% 50%, rgba(26, 26, 26, 0.03) 0%, transparent 50%);
    z-index: -1;
}

.hero-content {
    max-width: 700px;
    padding: 40px 0;
}

.hero-title {
    font-size: 72px;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 20px;
    letter-spacing: 2px;
}

.hero-subtitle {
    font-size: 28px;
    color: var(--text-light);
    margin-bottom: 20px;
    font-weight: 300;
}

.hero-desc {
    font-size: 18px;
    color: var(--text-light);
    margin-bottom: 40px;
    line-height: 1.8;
}

.hero-buttons {
    display: flex;
    gap: 20px;
    margin-bottom: 60px;
}

.hero-stats {
    display: flex;
    gap: 60px;
}

.stat-item {
    text-align: center;
}

.stat-number {
    display: block;
    font-size: 48px;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 8px;
}

.stat-label {
    font-size: 16px;
    color: var(--text-light);
}

/* 章节标题 */
.section-title {
    font-size: 42px;
    font-weight: 700;
    color: var(--primary-color);
    text-align: center;
    margin-bottom: 16px;
}

.section-subtitle {
    font-size: 18px;
    color: var(--text-light);
    text-align: center;
    margin-bottom: 60px;
}

/* 核心业务 */
.services {
    padding: 100px 0;
    background: var(--bg-color);
}

.services-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 40px;
}

.service-card {
    background: var(--bg-color);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    padding: 40px;
    transition: var(--transition);
}

.service-card:hover {
    transform: translateY(-10px);
    box-shadow: var(--shadow-hover);
    border-color: transparent;
}

.service-icon {
    width: 80px;
    height: 80px;
    background: var(--bg-light);
    border-radius: 16px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 24px;
    transition: var(--transition);
}

.service-card:hover .service-icon {
    background: var(--primary-color);
}

.service-icon i {
    font-size: 36px;
    color: var(--primary-color);
    transition: var(--transition);
}

.service-card:hover .service-icon i {
    color: #fff;
}

.service-card h3 {
    font-size: 24px;
    color: var(--primary-color);
    margin-bottom: 16px;
}

.service-card p {
    color: var(--text-light);
    margin-bottom: 20px;
    line-height: 1.7;
}

.service-features {
    list-style: none;
}

.service-features li {
    padding: 8px 0;
    color: var(--text-light);
    font-size: 14px;
    border-bottom: 1px solid var(--border-color);
}

.service-features li:last-child {
    border-bottom: none;
}

.service-features li::before {
    content: '•';
    color: var(--accent-color);
    margin-right: 10px;
}

/* 关于我们 */
.about {
    padding: 100px 0;
    background: var(--bg-light);
}

.about-content {
    display: grid;
    grid-template-columns: 1.2fr 1fr;
    gap: 80px;
    align-items: start;
}

.about-text p {
    color: var(--text-light);
    margin-bottom: 20px;
    line-height: 1.8;
    font-size: 16px;
}

.about-features {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 16px;
    margin-top: 30px;
}

.about-feature {
    display: flex;
    align-items: center;
    gap: 10px;
    color: var(--text-color);
    font-size: 15px;
}

.about-feature i {
    color: var(--accent-color);
    font-size: 18px;
}

.about-centers {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.center-card {
    background: var(--bg-color);
    border-radius: 12px;
    padding: 24px;
    display: flex;
    align-items: center;
    gap: 20px;
    transition: var(--transition);
}

.center-card:hover {
    transform: translateX(10px);
    box-shadow: var(--shadow);
}

.center-card i {
    font-size: 32px;
    color: var(--primary-color);
}

.center-card h4 {
    font-size: 18px;
    color: var(--primary-color);
    margin-bottom: 4px;
}

.center-card p {
    font-size: 14px;
    color: var(--text-light);
}

/* 发展历程 */
.timeline-section {
    padding: 100px 0;
    background: var(--bg-color);
}

.timeline {
    position: relative;
    max-width: 900px;
    margin: 0 auto;
    padding: 40px 0;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 50%;
    top: 0;
    bottom: 0;
    width: 2px;
    background: var(--border-color);
    transform: translateX(-50%);
}

.timeline-item {
    position: relative;
    padding: 20px 0;
    width: 50%;
}

.timeline-item:nth-child(odd) {
    padding-right: 60px;
    text-align: right;
}

.timeline-item:nth-child(even) {
    padding-left: 60px;
    margin-left: 50%;
}

.timeline-dot {
    position: absolute;
    width: 16px;
    height: 16px;
    background: var(--primary-color);
    border-radius: 50%;
    top: 50%;
    transform: translateY(-50%);
}

.timeline-item:nth-child(odd) .timeline-dot {
    right: -8px;
}

.timeline-item:nth-child(even) .timeline-dot {
    left: -8px;
}

.timeline-content {
    background: var(--bg-light);
    padding: 24px;
    border-radius: 12px;
    transition: var(--transition);
}

.timeline-content:hover {
    box-shadow: var(--shadow);
    transform: translateY(-5px);
}

.timeline-year {
    display: inline-block;
    background: var(--primary-color);
    color: #fff;
    padding: 4px 12px;
    border-radius: 20px;
    font-size: 14px;
    font-weight: 500;
    margin-bottom: 12px;
}

.timeline-content h4 {
    font-size: 20px;
    color: var(--primary-color);
    margin-bottom: 8px;
}

.timeline-content p {
    color: var(--text-light);
    font-size: 14px;
}

/* 平台入口 */
.platforms {
    padding: 100px 0;
    background: var(--bg-light);
}

.platforms-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 40px;
    max-width: 900px;
    margin: 0 auto;
}

.platform-card {
    background: var(--bg-color);
    border-radius: 20px;
    padding: 50px 40px;
    text-align: center;
    transition: var(--transition);
    border: 2px solid transparent;
}

.platform-card:hover {
    transform: translateY(-10px);
    box-shadow: var(--shadow-hover);
}

.platform-card.supplier-platform {
    border-color: var(--primary-color);
}

.platform-card.annotation-platform {
    border-color: var(--accent-color);
}

.platform-icon {
    width: 100px;
    height: 100px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 24px;
    transition: var(--transition);
}

.supplier-platform .platform-icon {
    background: rgba(26, 26, 26, 0.1);
}

.annotation-platform .platform-icon {
    background: rgba(230, 57, 70, 0.1);
}

.platform-icon i {
    font-size: 48px;
}

.supplier-platform .platform-icon i {
    color: var(--primary-color);
}

.annotation-platform .platform-icon i {
    color: var(--accent-color);
}

.platform-card h3 {
    font-size: 28px;
    color: var(--primary-color);
    margin-bottom: 16px;
}

.platform-card p {
    color: var(--text-light);
    margin-bottom: 24px;
    font-size: 15px;
}

.platform-card .btn {
    margin-bottom: 24px;
}

.platform-features {
    display: flex;
    justify-content: center;
    gap: 24px;
    flex-wrap: wrap;
}

.platform-features span {
    display: flex;
    align-items: center;
    gap: 6px;
    font-size: 14px;
    color: var(--text-light);
}

.platform-features i {
    color: var(--accent-color);
}

/* 联系我们 */
.contact {
    padding: 100px 0;
    background: var(--bg-color);
}

.contact-content {
    max-width: 800px;
    margin: 0 auto;
}

.contact-info {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 30px;
}

.contact-item {
    display: flex;
    align-items: flex-start;
    gap: 20px;
    padding: 24px;
    background: var(--bg-light);
    border-radius: 12px;
    transition: var(--transition);
}

.contact-item:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow);
}

.contact-item i {
    font-size: 28px;
    color: var(--primary-color);
    margin-top: 4px;
}

.contact-item h4 {
    font-size: 18px;
    color: var(--primary-color);
    margin-bottom: 8px;
}

.contact-item p {
    color: var(--text-light);
    font-size: 15px;
}

/* 页脚 */
.footer {
    background: var(--bg-dark);
    color: #fff;
    padding: 60px 0 30px;
}

.footer-content {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: 40px;
    margin-bottom: 40px;
}

.footer-brand .logo {
    margin-bottom: 16px;
}

.footer-brand .logo-text {
    color: #fff;
}

.footer-brand p {
    color: rgba(255, 255, 255, 0.7);
    font-size: 14px;
}

.footer-links h4,
.footer-social h4 {
    font-size: 16px;
    margin-bottom: 20px;
    color: #fff;
}

.footer-links {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.footer-links a {
    color: rgba(255, 255, 255, 0.7);
    text-decoration: none;
    font-size: 14px;
    transition: var(--transition);
}

.footer-links a:hover {
    color: #fff;
}

.social-icons {
    display: flex;
    gap: 12px;
}

.social-icon {
    width: 40px;
    height: 40px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: #fff;
    text-decoration: none;
    transition: var(--transition);
}

.social-icon:hover {
    background: var(--accent-color);
}

.footer-bottom {
    text-align: center;
    padding-top: 30px;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.footer-bottom p {
    color: rgba(255, 255, 255, 0.5);
    font-size: 14px;
}

/* 响应式设计 */
@media (max-width: 1024px) {
    .hero-title {
        font-size: 56px;
    }

    .services-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .about-content {
        grid-template-columns: 1fr;
    }

    .footer-content {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    .header .container {
        flex-wrap: wrap;
        height: auto;
        padding: 15px 20px;
    }

    .nav {
        order: 3;
        width: 100%;
        justify-content: center;
        gap: 20px;
        margin-top: 15px;
    }

    .header-actions {
        order: 2;
    }

    .hero-title {
        font-size: 42px;
    }

    .hero-subtitle {
        font-size: 22px;
    }

    .hero-buttons {
        flex-direction: column;
    }

    .hero-stats {
        flex-wrap: wrap;
        gap: 30px;
    }

    .services-grid {
        grid-template-columns: 1fr;
    }

    .timeline::before {
        left: 20px;
    }

    .timeline-item {
        width: 100%;
        padding-left: 60px !important;
        padding-right: 0 !important;
        text-align: left !important;
        margin-left: 0 !important;
    }

    .timeline-item .timeline-dot {
        left: 12px !important;
        right: auto !important;
    }

    .platforms-grid {
        grid-template-columns: 1fr;
    }

    .contact-info {
        grid-template-columns: 1fr;
    }

    .footer-content {
        grid-template-columns: 1fr;
        text-align: center;
    }

    .social-icons {
        justify-content: center;
    }
}

/* 动画效果 */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.hero-content,
.service-card,
.platform-card,
.contact-item {
    animation: fadeInUp 0.6s ease-out forwards;
}

.service-card:nth-child(2),
.platform-card:nth-child(2) {
    animation-delay: 0.2s;
}

.service-card:nth-child(3) {
    animation-delay: 0.4s;
}